Helianthus grosseserratus
sawtooth sunflower
Overview
Helianthus grosseserratus, sawtooth sunflower, is a tall, rhizome-spreading perennial of prairies and moist meadows that reaches 5–12 feet (1.5–3.7 m) tall. The smooth stems are often coated with a whitish, waxy bloom and rise in dense stands from creeping underground rhizomes. Its lance-shaped leaves are 4–8 inches (10–20 cm) long with sharply saw-toothed margins and a pale, finely hairy underside. From late summer into fall it carries yellow flower heads 2–3 inches (5–7.5 cm) across, each with 10–20 ray florets around a yellow central disc, held in open branched clusters. The seeds that follow feed finches and other birds, while the flowers draw bees and butterflies late in the season. It spreads quickly by rhizomes and seed to form large colonies, which can crowd out smaller plants in a bed. The species grows in damp, open ground along streams, ditches, and prairie swales across central and eastern North America. Tall stems may lean or topple in rich soil or wind without support.
Native Range
Helianthus grosseserratus is native to central and eastern North America, centered on the tallgrass prairie region from Manitoba and the Great Lakes south to Texas and east to the Appalachians. It grows in moist prairies, meadows, ditches, streambanks, and roadsides.Suggested Uses
Used in prairie and meadow restorations, rain gardens, naturalized borders, and pollinator and bird plantings. It suits large, open spaces with room to spread, though its height and rhizomes make it less suited to small, mixed beds.How to Identify
Appearance
Size & Dimensions
Height5' - 12'
Width/Spread2' - 4'
Bloom Information
Detailed Descriptions
Foliage Description
Green with pale undersideGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight